Island



W. A. HARRIS. OUT-OPP FOB. STEAM ENGINES.

3 Sheets-Sheet 1.

(No Model.) f

No. 469,696. Patented'Mar. 1, 1892.

3 S I R R A H A GUT-OFF FOR STEAM ENGINES.

No. 469,696. Patented Mar. 1, 1892.

WZZL'aJn/A (Nd Model.) 3 Sheets-Sheet 3;

W. ALHARRIS.

GUT-OFF FOR STEAM ENGINES. No. 469,696. Patented Mar. 1, 1892.

UNITED STATES PATENT OFFICE.

IVILLIAM A. HARRIS, OF PROVIDENCE, RI-IODE ISLAND.

CUT-OFF FOR STEAM-ENGINES.

SPECIFICATION forming part of Letters Patent No. 469,696, dated March 1,1892.

Application filed April 16, 1891.

To all whom it may concern.-

Be it known that 1, WILLIAM A. HARRIS, of Providence, county ofProvidence, State of Rhode Island, have invented an Improvement inAutomatic Out-Offs for Steam-Engines, of which the followingdescription, in connection with the accompanying drawings, is aspecification, like letters and figures on the drawings representinglike parts.

This invention relates to automatic cut-0E valve-gears of what arecommonly known as the Corliss type of steam-engines; and it has for itsobject to improve such valve-gears,

whereby a quicker and closer regulation of the cut-off may be effected,and, further, to effect a more uniform movement of the various parts.

In accordance with this invention the valvestem is moved by anactuating-arm, the same being actuated by means of a suitable connectionfrom an operating-lever, the said connection in effect engaging theactuating-arm with its operating-lever. A pivoted tripping device isprovided, which when moved acts at both sides of its pivotal center orfulcrum to operate on the said connection, to thereby disengage theactuating-arm from its operatinglever and permit the former to resumeits normal or closed position for the purpose of cutting oif the steam,as will be hereinafter described. The movement of the tripping device inthe present instance is effected by means of the cam and its yoke, to behereinafter referred to as forming another branch of my presentinvention.

One part of this invention therefore consists in an automaticvalve-gear, an actuatingarm for the valve-stem, an operating-lever forthe said actuating-arm, and an engaging connection between said membershaving engaging surfaces, combined with a tripping mechanism for saidconnection, which in operation moves the said surfaces in oppositedirections to sever or disengage the actuating-arm from itsoperating-lever; substantially as will be described. 7 Another part ofmy invention consists in an automatic cut-off, the combination, with acam, of a yoke adapted to act at opposite sides upon said cam and to bemoved thereby, and a tripping mechanism controlled by said yoke,substantially as will be described.

$erial No. 389,128. (No model.)

The other features of this invention will be hereinafter described, andfully pointed out in the claims.

Figure 1 represents in side elevation a sufficient portion of asteam-engine provided with my improved valve-gear to enable my inventionto be understood. Fig. 2, on an en-' larged scale, shows the cut-offmechanism for one of the valves; Fig. 3, a left-hand elevation of thesame. Figs. 4 and 5 show the out off mechanism in different positions.Figs. 6, 7, 8, and 9 show some of the parts detached; Figs. 10 andl1,partial vertical, longitudinal, and cross sections of the connectionor dog; Fig. 12, a diagram to be referred to; Figs. 13 and 14,modifications to be described.

Referring to the drawings, A represents the cylinder of an engine, whichcylinder is provided at its opposite ends with the usual steam andexhaust valves arranged and con structed in a manner common to enginesof the four-valve or Corliss type, the valve-stems a, of theexhaust-valves being provided with arms a, actuated by links a from theusual wrist-plate w, pivoted to the center of the cylshaft (notshown)and having its eccentric-rod connected to the wrist-pin w. Referring toFigs. 2 and 3, the valve-stem b of each steam-valve, mounted in asuitable support or bonnet B, has keyed or otherwise made fast to itsouter end, as herein represented, the bell-crank valve-actuating lever0, one arm 0 of which has jointed to it the usual drop-rod c, carryingat its lower end a weighted piston movingin a vacuum-chamber ordash-pot. (Not shown.) The other arm 0 of the said lever in the presentembodiment of my invention carries the tripping mechanism. Theparticular form of tripping mechanism which is herein shown and which Iprefer to employ comprises a trip-shaft (l, journaled in a hub c on theouter end of the arm 0 of the actuating-lever C, the said shaft dpresenting a preferably fiat face 5 and an engaging shoulder 6, adaptedto be engaged bya shoulder 9 on a dog or connection e,pivoted at e to anarm f of a preferably bellcrank operating-lever F, journaled on asuitable bearing or hub formed, as represented, on the bonnet B. (SeeFig. 3.) The hub 0 is inder-casting and taking its motion in usual Imanner from an eccentric placed on the crank- 1 1 milled or cut away atits upper side (see Figs. 3 and 7) for the dog or connection e,to permitthe said dog to engage the trip-shaft d. The arm f of theoperating-lever F is provided with a stud or pin f, to which is jointedone end of the usual actuating-link g, jointed at its opposite end tothe wrist-plateau, (see Fig. 1,) the said wrist-plate when rockedtransmittinga corresponding movement to the lever F, causing theshoulder 9 on the dog or connection e to engage the shoulder 6 on thetrip-shaft d and turn orrock the lever C and valve-stem b to admit steamto that end of the cylinder. To disengage the trip-shaft d from the dogor connection 6 before the latter has completed its forward movement andthus out off the admission of steam to the cylinder at some point earlyin the stroke, the said trip-shaft has fast to its inner end a forkedarm or yoke (1', having rolls d journaled in its ends, which act atopposite sides upon the surface cam D, herein shown as forming a part ofthe sleeve D, jonrnaled on a bearing or hub on the bonnet B and providedwith an arm D to which is connected a controllingrod D moved by anydesired governing mechanism. (Not shown.)

The cam D, as herein shown, comprises two idle or concentric surfaces 1012, one of the rolls d normally bearing against one of the concentricsurfaces and the other roll 01 hearing against the other concentricsurface; but when the trip-shaft d and the actuating-arm O are moved bythe dog or connection e about the. axis of the valve-stem b the yokewill also be moved about the cam D, the rolls (1 running upon theconcentric surfaces until they reach the working surfaces 15 16, whichsurfaces will act upon the rolls to turn or rotate the yoke about itsaxis, rotating the trip-shaft d sufficiently to disengage its shoulder 6from the shoulder 9 on the dog or connection e and permit the drop-rod cto immediately return the arm 0 and its valve-stem b to their normalclosed position, Figs. 2- and 5, to cut off the steam from that end ofthe cylinder.

The shoulder 6 on the trip-shaft d is herein represented as formed byahardened steel or other block 8, fitted in a suitable recess milled inthe shaft, the said block being held in position by bolts or screws 8'.The block .9 is preferably made double the length of the engagingsurfaces to permit the block to be turned end for end, in order thatboth ends may be utilized. The block is also counterbored at itsopposite sides to permit it to be turned, in order that bothedges ofeach face may be utilized for the shoulder 6.

The shoulder 9 on the dog or connection e is herein represented asformed by a hardened steel block (3?, fitted in asuitablegroove milledinthe dog and held in place bya bolt e and mute. The block 6 ispreferably counterboredat its opposite sides to receive the head e ofthe bolt 6 thus permitting the block to beturned or reversed toutilizeboth edges of all its faces for the shoulder 9 as one or anotherof them becomes worn, each of the said faces being properly shaped, asshown, for this purpose.

Assuming the parts to be in the position shown in Fig. 2, the operationof my improved valve-gear is as follows: As the pistonin the cylinderapproaches the inner or left-hand end of the cylinder, Fig. 1, thewrist-plate will be moved to the right, as indicated by the arrowthereon, and, acting through the link g, will turn or rock theoperating-lever F in the direction of arrow 25, Fig. 2, causing shoulder9 on the dog or connection e to engage the shoulder 6 on the trip-shaft(Z and push the same and its actuating-arm C before it, rotating thevalve-stem, as shown at the left in Fig. 1, to admit steam to that endof the cylinder and lift the drop-rod c. As the actuating-arm and valveare rotated, the yoke at will be moved about the cam D until its rolls(I reach the working surfaces 15 16 thereon, when the said yoke will beturned or rotated about its axis into the position shown in Fig. 4,thereby rotating the tripshaft at sufficiently to disengage its shoulder6 from the shoulder 9 on the dog, as shown in said figure, and permitthe drop-rod c to return the actuating-arm O and its valve quickly totheir normal or closed position, as shown in Fig. 5, to cutoff the steamfrom that end of the cylinder, the lever F and its dog or connection 6continuing to the end oftheir movement, the dog riding over the surface5 of the trip-shaft. As the steam-arm C and its valve-are returned totheir normal positions, Figs. 2 and 5, the yoke is moved back about thecam D to its former normal position, turning the trip-shaft cl intoposition again for its shoulder 6 tobe again engaged by the shoulder 9on the dog pr connection e when the latter is drawn back by the returnmovement of the lever F to its first position, Fig. 2, ready for thebeginning of a new stroke of the piston. As the speed of the enginevaries, the governor will operate through the rod D to rotate the cam Dabout its hearing, so that the rolls d on the yoke d will reach theworking surfaces of the cam earlier or later in the stroke, and thusgive to the engine an earlier or later cut-off.

In automatic cut-olfs of this class as heretofore constructed, so far asI am aware, there has been provided a stationary member and a hookingmember to co-operate therewith, the operation of unhooking having beenperformed entirely by movement of the hooking member alone. It thereforefollows that the time consumed in unhooking is the length of timerequired forthe moving of this hooking member from the other orstationary member, whereas in this my present invention the trip-. shaftis so moved as to causeit on one. side of its fulcrum to be movedawayfrom the hook- .ing member and partly nnhook the parts,

while at the same time another portion of said trip-shaft on theopposite side of its axis or fulcrum acts upon the hooking member toengagement with said trip-shat t, the resultant of the two movementsbeing equivalent to the heretofore single movement of the hooking memberof the other and prior contrivances, whereby in the present instance Iam enabled to disengage the parts in less time than formerly. Forinstance, by reference to Fig. 12, when the rolls in the yoke reach theworking surfaces of the cam the shaft cl will be rotated in thedirection of the arrow from its full-line position to its dotted-lineposition 1 2, the heel 7 of the face 5 acting at the same time againstthe under side of the dog or connectione, lifting the same into itsdotted-line position 1 3 to assist in disengaging the shoulder 6 fromthe shoulder 9 on the dog. It is necessary, therefore, to rotate theshaft 6?. a distance substantiallyequal to one half only of the depth ofthe engaging shoulder?) on the dog, for the reason that the heel 7 oftheface 5 moves or lifts the dog itself the other half or the remainingdistance, and as both the tripsh'aft and dog are moved at the same timein opposite directionsit requires only one-half the time for theoperation of tripping as has heretofore been required where one memberonly was made movable, and not only is the time re-.

quired for hooking and unhooking greatly reduced, but the work thrownupon the governor is further greatly reduced by reason of the increasedleverage gained by reason of the difference between the radial length ofthe yoke d and the radial distance from the shoulder 6 and heel 7 to thecenter of the shaft (1, and further by the difference between the radialdistance of the shoulder 6 and heel 7 from the center of the shaft (1and the length of the dog or connection 6, so that a very slightthrustexerted upon the cam is sufficient to easily and quicklyunhook ortrip the connection 6 and shaft (1.

By employing the yoke 61', acting at opposite sides'of the cam D, I amenabled to use the well-known form of surface cam and dispense with thespring heretofore employed and at the same time get a positive andcertain movement of the parts in both directions, while at the sametime, not being put to the necessity of employing expensive groovecams,and by reason of the arms of the yoke acting at opposite sides of thesaid surfacecam, the movement of one arm of the yoke equalizes orcounterbalances the movement and strain of the other arm of the yoke,thus obtaining a more even and uniform motion and taking undue strainfrom the governor.

The point at which the actuating force is applied, the point ofsuspension of the dog or connection e, and the point of. contact of theshoulder 9 on said dog are preferably equidistant from the center ofrotation of the valve-stem b, as shown,the forces'thus acting in thesame are and avoiding lateral strain and uneven movements. The curvegiven to the dog or connection 6 will preferably be such that the dogwill be supported in a substantially fixed position with relation to itscenter of rotation as it is drawn back over the trip-shaft.

The yoke 61'', being carried by the valve-actuating arm, is returned toits normal position immediately after performing its functionviz., thetripping of the dog or connection e-thus bringing the parts to a stateof rest as soon as their work is completed.

If for any reason the drop-rod 0' should fail to return the actuatingarmand its valve to their normal closed positions when properly released,they will be positively returned upon the return movement of the dog orconnection e by a hook 50 on the end thereof, as shown.

The valve-actuating mechanisms for the steam-valves are precisely alikein construction and operation, except they are reversed and operate inopposite directions, and for this reason the arms D controlling the camsD for the steam-valves, are placed at the opposite sides of theirpivotal centers, they being connected by a rod D (see Fig. 1) to operateor move in unison.

Fig. 13 shows a modified form of contrivance embodying my invention,wherein the operating-lever F- carries the connection e in such mannerthat it acts like a hook to pull or draw the actuating-arm C after it inits movement rather than to push it before it, as in Figs. 1 to 12,inclusive, the tripping mechanism being, however, the same in bothinstances.-

Fig. 14 shows another modification embodying my invention,'wherein theconnection 6 is carried by the actuating-arm C and the trip-shaft andthe yoke 61 are carried by the operating-lever F. In this instance thetripshaft moves continuously with the operatinglever independent of themovement of the valve-actuating arm, the cam being slightly changed inform, as shown, to give the proper release to the tr pping mechanism.

This invention is not limited to the particular arrangement andconstruction shown, as it is evident the same may be varied and stillcome within the scope of the invention.

I claim 1. In an automatic valve-gear, an actuatingarm for thevalve-stem, an operating-lever for the said actuating-arm, and anengaging connection between said members having engaging surfaces,combined with a tripping mechanism for said connection, which inoperationmoves the said surfaces in opposite directions to sever ordisengage the actuatingarm from its operating-lever, substantially asdescribed.

2. In an automatic valve-gear, an actuatingarm for the valve-stem, anoperating-lever for the said actuating-arm, and an engaging connectionbetween said members having engaging surfaces, combined with a trippingmechanism for said connection, which in operation moves the saidsurfaces in opposite directions to sever or disengage the actuatingarmfrom its operating-lever, the combined movement of the said engagingsurfaces in opposite directions being equivalent to the bite or hold ofsaid engaging surfaces when in engagement, substantially as described.

An actuating-arm for the valve-stem, and an operating-lever therefor,and an intermediate connection joining said members, combined with atripping device, the movement of which at both sides of its fulcrum isutilized to disengage said members, substantially as described. 1

4. An automatic valve-gear containing the following instrumentalities,viz: a valvestem, an actuating-arm therefor, a trip-shaft journaled inthe said actuatingarm and means to rotate the same in said actuatingarm,an operating-lever, and-a connection carried by said lever to move saidactuating-arm to operate substantially as described.

5. An automatic cut-off valve-gear containing the followinginstrumentalities, viz: a valve-stem, an actuating-arm therefor, atripshaft journaled in the said actuating-arm, a cam and meanscontrolled thereby to rotate said trip-shaft in its journal-bearing, anoperating-lever, and a connection carried by said operating-lever tomove the said actuatingarm, substantially as described.

6. An automatic cut-off valve-gear containing the followinginstrumentalities, viz: an actuating-arm for the valve-stem, an operating-lever, and a connection between said members to move the former by thelatter, and a tripping device movable withand carried by the saidactuating-arm to disengage said members, substantially as described.

7. In an automatic cut-off, the combination, with a cam,of a yokeadapted to act at opposite sides upon said cam and to be moved thereby,and a tripping mechanism controlled bysaid yoke, substantially asdescribed.

8. In an automatic valve-gear, a valve-stem, an actuating-arm therefor,a trip-shaft d, journaled in said arm, a cam, and a yoke 01', acting atopposite sides thereon, combined with an operating-lever, means to movethe same, and a dog carried thereby to engage said tripshaft, to operatesubstantially as described.

9. In anautomatie valve-gear,a valve'stem, an actuating-arm therefor, atrip-shaft d, journaled in said arm and formed to present asubstantiallyflat face 5,a shoulder 6 and heel 7, the yoke d, and a camto move the same,

combined with an operating-lever, means to move it, and a dog e, carriedthereby and presenting a shoulder 9, to operate substantially asdescribed.

10. In an automatic valve-gear, a valve-stem, an actuating-arm therefor,a trip-shaft d, journaled in said arm and formed to present asubstantially flat face 5, a shoulder 6 and heel 7, the arm cl, and acam to move the same, combined with an operating lever, means to moveit, a dog e, carried thereby, and the block 6 counterbored at itsopposite sides, to operate substantially as described.

11. In an automatic valve-gear, a valve-stem, an actuating-arm Otherefor, the drop-rod a, shaft d, arm d, and cam D, combined with theoperating-lever F, means to move the same, and the dog 2, all to operatesubstantially as described. I

12. In an automatic valve-gear, a valve-stem, an actuating-arm therefor,a trip-shaft cl, journaled in said arm and formed to present asubstantially flat face 5, a shoulder 6 and heel 7, the yoke d, and acam to move the same, combined with an operatinglever, means to move it,and a dog e, carried thereby and presenting a shoulder 9 and hook 50,all to operate substantially as described.

13. In an automatic valve-gear, a valve-stem and actuating-arm therefor,an operating-lever, and a connection between, the said actuating-arm andoperating-lever, combinedwi-th the trip-shaft d, means to rotate it inits hearing, and the block 8, to operate substantially as described.

14.. An actuating-arm for the valve -stem and an operating levertherefor, combined with a curved dog or connection joining said membersand a tripping device therefor, the curve of the said dog or connectionbeing such as to support it during operation in a substantially fixedposition with relation to its center of rotation, substantially asdescribed.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

WILLIAM A. HARRIS. Witnesses:

BERNICE J. NoYEs, EDWARD F. ALLEN.

